Crop protection involves application of herbicides, insecticides, fungicides, collectively known as pesticides, to control the growth of weeds, harmful insects and plant diseases that afflict crops. Without these practices, food production would decline, many fruits and vegetables would be in short supply, and the price of food would rise. Further, fibers for textile manufacturing, such as cotton, would decrease as farmers would lose their harvests due to pests and diseases.
Pesticides are typically applied in combination with adjuvants to improve pesticide performance. Adjuvants are substances in a pesticide formulation or added to the spray tank to improve pesticidal activity or application characteristics. In addition, micronutrients may be applied in combination with pesticides and adjuvants. Micronutrients includes elements essential for plant growth and include boron (B), copper (Cu), iron (Fe), chloride (CI), manganese (Mn), molybdenum (Mo) and zinc (Zn). For instance, boron assists plants in use and regulation of other nutrients, aids production of sugar and carbohydrates, and is required for seed and fruit development. Copper is important for reproductive growth, aids in root metabolism and helps in the utilization of proteins. Chloride aids plant metabolism. Iron is a necessary micronutrient in the formation of chlorophyll. Manganese is used by plant enzyme systems and is involved in the breakdown of carbohydrates, as well as nitrogen metabolism. Molybdenum assists in the use of nitrogen. Zinc is needed by the plant for regulating plant growth and in carbohydrate and sugar metabolism. While some micronutrients are found in soil, others are not; and some soil-based micronutrients may not be at levels sufficient for plant growth.
However, many pesticides contain phosphate salts that bind to the metal ions of the micronutrient and convert them to insoluble solids before the micronutrient can be absorbed by the plant, rendering micronutrient ineffective. In prior approaches, ethylenediaminetetraacetic acid (EDTA) has been used as a chelating compound that operates to bind metal ions of the micronutrient and prevents phosphate salt from converting the micronutrients to insoluble solids. While EDTA prevents phosphate from binding to metal ions, the metal ions exhibit diminished reactivity and the EDTA can cause phytotoxicity. In addition, EDTA is not accepted for use as a chelator in all countries. Other chelating compounds include organic acids and amino acids such as those described in U.S. Pat. No. 5,504,055 and US Patent Application Publication 2005/239673, which are incorporated herein for any purpose.